Colorimetry
                     COLORIMETRY
INTRODUCTION
 Colorimetry has been around since the 1870s when 
Jules Dubosq invented the colorimeter.
 In 1885 Joseph William Lovibond devised a method of 
measuring colors with a handheld comparator while 
working in his father's brewery.
A TECHNIQUE
 Colorimetry is a technique for measuring the 
concentration of a known constituent in a solution 
compared to standard solutions. 
ABOUT COLORIMETRY
 The human eye perceives light and color in a very 
subjective way. Science demands an objective way of 
measuring things, which is colorimetry. 
 Mathematically, the Beer-Lambert Law, which is a 
combination of two laws, defines colorimetry.
BEER-LAMBERT LAW
 Beers Law says that if monochromatic light passes through 
a homogenous solution, the amount of light transmitted is 
directly proportional to the solute in the solution.
 Lamberts Law states that the length of the path 
determines the absorbance of light by a colored solution 
and the volume of liquid it passes through
COLORIMETRY USES BEER-LAMBERT LAW
 Colorimetry uses this law to measure the absorbance 
(more frequently) or light transmittance to determine 
solution concentrations. 
 The solution must not fluoresce, and there should be no 
temperature change during the measuring process.
COLOR COMPARATORS AND COLORIMETERS
 The principle of Lovibond's comparator is still in use 
today, and indeed the "Lovibond Comparator" is still a 
brand of the Tintometer company in the UK. 
 This type of colorimeter, sometimes called a "Filter 
Photometer," consists of a handheld cube with space for 
two cuvettes into which liquids for analysis are placed. 
AN ILLUMINANT
  A specific light source (daylight in a comparator), 
usually an LED or incandescent light, which projects a 
fixed, consistent light onto an object.
AN OBSERVER
 A specified field of view to analyze colors. A standard 
observer is usually two degrees in a colorimeter
USES OF COLORIMETRY
 Colorimetry is used in monitoring to measure bacterial 
growth rates, quality, and color in food and beverage 
manufacturing, textiles manufacturing, cosmetics, paint 
works, and the petroleum industry.
THANK YOU